1. Field of the Invention
The present invention relates to an improved process for drying of acid whey and/or acid whey permeate. More particularly, the present invention relates to a process for spray drying the acid type of cheese whey or casein, partially delactosed acid whey or an acid permeate obtained by ultrafiltration of acid whey and/or acid cheese milk. This is accomplished by injecting a dry neutralizing edible calcium or magnesium salt during the spray drying of the acid whey and/or permeate products and drying the resulting product.
2. Description of the Prior Art
It is well known that the spray drying technology leads to severe clogging of the spray tower and the associated cyclone if acid whey and/or acid permeate are spray dried. This situation results in very short running times and therefore, makes it impossible to handle the increasing amount of acid whey and/or acid permeate resulting from fresh cheese production. The fouling and clogging within the spray tower can be partly reduced by adding approximately 30 to 40% by weight of sweet whey to the acid mix or adding a lesser amount of sweet whey with an inert anti-caking agent. Other methods used include U.S. Pat. No. 3,615,664 issued Oct. 26, 1971, which utilizes a process for demineralization of a high heat treated delactosed whey and also provides whey processing steps to improve drying characteristics of the material. This is accomplished by crystallizing the liquid whey product and removing the lactose crystals. The resulting whey is clarified and adjusted to a pH of 3.9 to 4.2 for cheddar cheese whey and 4.65 to 6.5 for sweet whey, subjecting the clarified whey to electrodialysis, concentrating the electrodialyzed material and spray drying the resulting product. U.S. Pat. No. 4,057,655, issued Nov. 8, 1977, describes a process for preparing a free flowing lactulose-containing powder from whey solutions or permeates by adding calcium hydroxide to adjust the pH to 9.4 to 11.2, heating the solution to reduce the pH to 7.5 to 9, then homogenizing, concentrating and drying the resultant product. This patent refers to the use of calcium hydroxide for conversion of lactose into lactulose. U.S. Pat. No. 4,088,791, issued May 9, 1978, describes a process for making a free flowing modified whey powder by forming an emulsion of titanium dioxide, fat and water, neutralizing (pH 6.7 to 7.4) the emulsion and adding the emulsion to a concentrated whey and spray drying the product. The neutralization step is accomplished by the addition of calcium lactate or a combination of calcium carbonate or calcium hydroxide, aluminum hydroxide and magnesium carbonate.